Research on the Mechanism of Corn Price Formation in China Based on the PLS-SEM Model.

After the cancellation of the temporary corn storage system in 2016, the price of corn in China returned to market regulation, resulting in increased price volatility. This study focuses on monthly data from April 2016 to March 2023 in China. The partial least squares structural equation modeling (PLS-SEM) is employed to analyze the impact of corn supply and demand factors, substitute prices, monetary supply, international corn prices, and international energy prices on the volatility of corn prices in China. Results indicate that supply and demand factors are the most direct influencers of corn prices, with demand factors having the most significant impact. Monetary supply and substitute prices affect corn prices through the demand side. External factors mainly consist of international energy and corn prices. The impact of international energy on Chinese corn prices is achieved through international corn prices, which directly influence the prices in China. It is recommended to stabilize corn market prices by regulating corn supply and demand, to improve the monitoring and early warning mechanisms for international energy and corn prices, and to implement measures for prudent regulation of monetary supply.

LC-MS/MS Method Assay for Simultaneous Determination of the Apixaban and Metformin in Rat Plasma: Assessment of Pharmacokinetic Drug-Drug Interaction Study.

A simple, sensitive and accurate LC-MS/MS method was developed and validated for the simultaneous quantification of apixaban (APB) and metformin (MET) in rat plasma using rivaroxaban as internal standard (IS). An Inertsil ODS3 C18 column (150 × 4.6 mm, 5 µm) was used for chromatographic separation with isocratic elution. Multiple reaction monitoring (MRM) using positive-ion ESI mode to monitor ion transitions of m/z 459.8 â†’ 442.8 for APB, m/z 130.2 â†’ 71.2 for MET, m/z 436.8 â†’ 144.9 for IS. The procedure of method validation included selectivity, linearity, precision, accuracy, matrix effect, extraction recovery and stability were conducted according to the guidelines of EMA and FDA. The method was validated over the concentration range of 0.5-250 ng/mL for APB and 8-8000 ng/mL for MET. The intra- and inter-day precision and accuracy of the quality control samples exhibited relative standard deviations (RSD) < 12.5% and the accuracy values ranged from -8.6 to 12.4%. Recovery and matrix effect values variations were all less than 15%. After oral administration APB and MET to rats, the comparison of pharmacokinetic parameters of APB in the single and co-administrated groups showed significant difference in AUC(0-t) from 730.71 ± 121.31 to 573.07 ± 90.13 ng/mL·h, t1/2 from 5.86 ± 3.21 to 4.24 ± 1.15 h and Cmax from113.54 ± 24.04 to 159.42 ± 54.6 ng/mL. The comparison of pharmacokinetic parameters of MET in the single and co-administrated groups showed significant difference in t1/2 from 2.83 ± 1.81 to 3.97 ± 0.57 h and Cmax from 4015.76 ± 873.23 to 3153.6 ± 1012.51 ng/mL. The results indicated that drug-drug interactions (DDI) occurred might be owing to APB affect one or all of OCTs, MATE1, MATE2-K.

The Effect of the "Triple-Layer Medical Security" Policy on the Vulnerability as Expected Poverty of Rural Households: Evidence from Yunnan Province, China.

China launched the "critical battle against poverty" nationwide in 2012. As its main battlefield, Yunnan province promulgated the "triple medical security" (TMS) policy in 2017. This study, based on the pooled cross-section database of 2015-2020 of registered poor households in Yunnan province, employed the logit model to examine the effect of TMS on the vulnerability as expected poverty (VEP) of these households. It found that increasing the reimbursement rates for overall medical expenses and inpatient expenses and decreasing the proportion of out-of-pocket medical payment to income reduced the VEP; increases in the number of sick people in the family increased its VEP, and although the increase in the reimbursement rate for overall medical expenses or for inpatient expenses partially offset the VEP caused by the increase in the number of chronically ill people in the family, the VEP caused by the increase in the number of critically ill people would increase in the short term with the increase in the reimbursement rate for overall medical expenses or for inpatient expenses. The findings help improve policies concerning the medical security and health of the rural poor population, providing theoretical reference and practical guidance for future research.

Prevalence and Risk Factors of Home Quarantine Strategy Implementation Among Chinese Residents During the Coronavirus Disease 2019 Pandemic.

Background: Home quarantine is an important strategy to contain the mass spread of the coronavirus disease 2019 (COVID-19) pandemic. However, there are a dearth of studies on the prevalence and risk factors of home quarantine strategy implementation among residents. This study aims to assess the state of home quarantine strategy implementation among Chinese residents, which could provide a reference for quarantine policymakers around the world during the pandemic. Method: We conducted a cross-sectional survey of 3,398 residents in China by adopting a convenience sampling strategy. We measured the prevalence and risk factors of home quarantine strategy implementation with the Center for Epidemiological Studies-Depression Scale (CES-D), 10-item Connor-Davidson Resilience Scale (CD-RISC 10), and Perceived Social Support Scale (PSSS). A multivariable model was used to determine the factors associated with home quarantine strategy implementation. Results: A total of 2,936 (86.4%) respondents carried out home quarantine. There were some factors significantly associated with home quarantine strategy implementation among Chinese residents during the COVID-19 outbreak. Respondents who were male, lived in western and central China, were aware of the primary symptoms of COVID-19, were willing to accept recommendations on relevant protective measures, understood local quarantine measures, had better resilience, and had better social support were more likely to engage in home quarantine. Respondents who were married, were employed, were healthy, and had high depression scores were more likely to refuse to follow home quarantine guidance. Conclusions: Gender, region, marital status, employment status, health status, awareness of the primary symptoms of COVID-19, willingness to accept recommendations on relevant protective measures, understanding of local quarantine measures, depression, psychological resilience, and perceived social support were the main factors affecting the implementation of residents' home quarantine strategy. Health service policymakers should adopt relevant measures to improve the prevalence of home quarantine strategy implementation among residents during the pandemic.

Comparison of yield and relative costs of different screening algorithms for tuberculosis in active case-finding: a cross-section study.

BACKGROUND: Part of tuberculosis (TB) patients were missed if symptomatic screening was based on the main TB likely symptoms. This study conducted to compare the yield and relative costs of different TB screening algorithms in active case-finding in the whole population in China. METHODS: The study population was screened based on the TB likely symptoms through a face-to-face interview in selected 27 communities from 10 counties of 10 provinces in China. If the individuals had any of the enhanced TB likely symptoms, both chest X-ray and sputum tests were carried out for them furtherly. We used the McNemar test to analyze the difference in TB detection among four algorithms in active case-finding. Of four algorithms, two were from WHO recommendations including 1a/1c, one from China National Tuberculosis Program, and one from this study with the enhanced TB likely symptoms. Furthermore, a two-way ANOVA analysis was performed to analyze the cost difference in the performance of active case-finding adjusted by different demographic and health characteristics among different algorithms. RESULTS: Algorithm with the enhanced TB likely symptoms defined in this study could increase the yield of TB detection in active case-finding, compared with algorithms recommended by WHO (p < 0.01, Kappa 95% CI: 0. 93-0.99) and China NTP (p = 0.03, Kappa 95% CI: 0.96-1.00). There was a significant difference in the total costs among different three algorithms WHO 1c/2/3 (F = 59.13, p < 0.01). No significant difference in the average costs for one active TB case screened and diagnosed through the process among Algorithms 1c/2/3 was evident (F = 2.78, p = 0.07). The average costs for one bacteriological positive case through algorithm WHO 1a was about two times as much as the costs for one active TB case through algorithms WHO 1c/2/3. CONCLUSIONS: Active case-finding based on the enhanced symptom screening is meaningful for TB case-finding and it could identify more active TB cases in time. The findings indicated that this enhanced screening approach cost more compared to algorithms recommend by WHO and China NTP, but the increased yield resulted in comparative costs per patient. And it cost much more that only smear/bacteriological-positive TB cases are screened in active case-finding.

Assessment of the oral health behavior, knowledge and status among dental and medical undergraduate students: a cross-sectional study.

BACKGROUND: It is widely accepted that oral health plays an important role in overall health. Both dental and medical students are expected to possess good oral health awareness and work together for public oral health promotion especially in developing countries like China. The aim of this study was to assess the oral health knowledge, behavior and status of dental and medical undergraduate students in the first (fresh) and third year (before specialized courses) study. METHODS: A self-administered structured questionnaire with 13 questions was designed based on oral health knowledge, behavior and status and a cross-sectional study was conducted among the 1st, 3rd year dental students (1DS, 3DS) and medical students (1MS, 3MS) of Sichuan University in Chengdu, China, in the period of September-December 2017. The data was analyzed by chi-square test using IBM SPSS Statistics v. 21.0. RESULTS: The oral health behavior, consciousness and status of the 1st, 3rd year medical and dental students were not optimistic. Dental freshmen were slightly superior to the medical ones in terms of the brushing methods and the awareness of oral disease-systemic disease relationship. The junior dental students showed highly significant improvement than their counterparts, mainly in the items about frequency of brushing teeth, brushing methods of vertical scrub or Bass technique (66.3%), usage of floss or mouth wash (49.7%), causes of caries, periodontal diseases and system diseases (56.9-83.4%). The rates mentioned above were 36.1, 15.8%, 26.7-43.6% among 3MS, respectively. In terms of oral health status, significant differences were only observed in junior students. The prevalence rates of bad breath, gum bleeding, and tooth discoloration among 3DS were obviously lower than those of 3MS. However, only a total of 17.2% junior students had a good oral health, including 23.8% dental students and 11.4% medical students. CONCLUSIONS: Our study provided a new understanding of oral health knowledge, behavior and status among dental and medical students, which may help to promote the reform of oral health education and establish a model for clinicians and dentists to work together for improving oral health.

Economic Pressure and Loneliness in Migrant Children in China: The Mediating Roles of Parent-Child Communication and Parental Warmth.

The purpose of the current study was to examine the mediating roles of parent-child communication and parental warmth in the relationship between economic pressure and loneliness in a sample of migrant children in China. A total of 437 participants were selected from two public schools for migrant children in Zhejiang Province, China. All participants were asked to complete four measures, including the Perceived Economic Strain Scale, the Parent-Child Communication Questionnaire, the Parental Warmth Scale, and the Children's Loneliness Scale. The results showed that economic pressure was positively and directly related to loneliness. Furthermore, parent-child communication and parental warmth partially mediated the relationship between economic pressure and loneliness in migrant children. Thus, parent-child communication and parental warmth play important roles in reducing the negative effect of economic pressure on loneliness in migrant children.

Initial Assessment of the LEO Based Navigation Signal Augmentation System from Luojia-1A Satellite.

A low Earth orbiter (LEO)-based navigation signal augmentation system is considered as a complementary of current global navigation satellite systems (GNSS), which can accelerate precise positioning convergence, strengthen the signal power, and improve signal quality. Wuhan University is dedicated to LEO-based navigation signal augmentation research and launched one scientific experimental satellite named Luojia-1A. The satellite is capable of broadcasting dual-frequency band ranging signals over China. The initial performance of the Luojia-1A satellite navigation augmentation system is assessed in this study. The ground tests indicate that the phase noise of the oscillator is sufficiently low to support the intended applications. The field ranging tests achieve 2.6 m and 0.013 m ranging precision for the pseudorange and carrier phase measurements, respectively. The in-orbit test shows that the internal precision of the ephemeris is approximate 0.1 m and the clock stability is 3 × 10-10. The pseudorange and carrier phase measurement noise evaluated from the geometry-free combination is about 3.3 m and 1.8 cm. Overall, the Luojia-1A navigation augmentation system is capable of providing useable LEO navigation augmentation signals with the empirical user equivalent ranging error (UERE) no worse than 3.6 m, which can be integrated with existing GNSS to improve the real-time navigation performance.

Voxel-by-voxel 4D flow MRI-based assessment of regional reverse flow in the aorta.

BACKGROUND: Complex and reverse flow in the aorta has been implicated in aneurysm development and stroke via retrograde embolization. PURPOSE: To evaluate global and regional differences between standard 2D plane-based and volumetric voxel-based quantification of regional forward/reverse flow, and reverse flow fraction (RFF) in the aorta. STUDY TYPE: Retrospective. SUBJECTS: In all, 35 subjects: 10 healthy controls (age: 57 ± 7 years, nine male), nine patients without aortic valve regurgitation (AR) (age: 63 ± 10 years, seven male), six patients with mild AR (age: 66 ± 6 years, five male), and 10 with moderate or severe AR (age: 60 ± 16 years, eight male). FIELD STRENGTH/SEQUENCE: 4D flow MRI (3T and 1.5T) was employed to acquire 3D blood flow velocities with entire thoracic aorta in all subjects. ASSESSMENT: Data analysis included standard 2D plane-based quantification of forward/reverse flow, and RFF-plane. In addition, a new semiautomatic workflow based on 3D segmentation and extraction of an aorta centerline was developed for voxel-by-voxel visualization (forward/reverse flow and RFF-voxel maps) and quantification of regional voxel-by-voxel forward/reverse flow in the entire thoracic aorta. STATISTICAL TESTS: Kruskal-Wallis tests were performed to test for differences between groups. A two-sample t-test or Wilcoxon rank sum test was used to compare voxel-based and plane-based results. RESULTS: Semiautomatic plane-based analysis showed excellent agreement with standard manual plane-based analysis for net flow and RFF-plane (RFF-plane: y = 0.99x-0.0, net flow: y = 1.00x-0.21, R > 0.99, P < 0.0001). Voxel-by-voxel maps demonstrated marked regional flow reversal in the ascending aorta in all patients and RFF-voxel was significantly increased (P < 0.001) compared to RFF-plane for all four groups, with the most pronounced differences for mild AR (18.0 ± 15.2% vs. 4.7 ± 5.4%). Voxel-based flow and RFF-voxel along the aorta showed areas with marked regional flow reversal (eg, vortex flow) compared to plane-based analysis. DATA CONCLUSION: Voxel-based analysis demonstrated regional flow reversal that was not detected by plane-based analysis. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:1276-1286.

[Application of melting curve assay in the quality assessment of drug susceptibility test on Mycobacterium tuberculosis].

OBJECTIVE: To evaluate the feasibility of melting curve assay technologies in quality assessment of drug susceptibility test (DST) on Mycobacterium tuberculosis. METHODS: During May 2009 to September 2012, a total of 2 204 MTB isolates were collected in Shanghai Songjiang District and 5 other county level TB institutes. DST results of these isolates were verified by the melting curve assay. Isolates with inconsistent phenotype and genotype results were retested and sequenced for any drug resistance mutations. RESULTS: Evaluation at Songjiang District showed high consistency of the melting curve assay with rifampicin and isoniazid DST results (kappa = 0.97 and 0.99, respectively). Consistency of the two methods were 97.6% (41/42), 100% (757/757) and 99.9% (788/799) in rifampicin resistant, susceptible, and total cases, respectively. As for isoniazid resistance detection, the consistency were 100% (72/72), 99.9% (726/727), and 99.9% (798/799) in resistant, susceptible, and total cases, respectively. Blinded re-examination of isolates with inconsistent genotype and phenotype resistance confirmed the good reproducibility of melting curve assay, which yielded the same results as the first test. Quality assessment at institutes A,B, C,D and E, however, showed consistency of only 87.5% (21/24), 80.8% (21/26), 87.5% (14/16), 82.9% (29/35), 60.9% (14/23) in rifampicinresistant cases, and 88.2% (30/34), 65.6% (21/32), 85.0% (17/20), 68.3% (41/60), 62.5% (15/24) in isoniazid resistant cases. As the reliability of DST results significantly varied among different areas, our finding indicated that there were misdiagnosed drug resistant cases in some field sites. CONCLUSION: The melting curve assay for MTB DST is fast, easy to use, reproducible, and able to identify mistakes in daily work. Therefore, it is a suitable tool for the quality assessment of conventional DST results.

Efforts to reduce the disparity between permanent residents and temporary migrants: Stop TB experiences in Shanghai, China.

OBJECTIVE: Eight of 17 districts of Shanghai have offered transportation and living allowances subsidies to patients with tuberculosis (TB) among the migrant population. The study aimed to assess the impact of the subsidising initiative on the treatment success rate (TSR) and identify the social determinants of treatment outcomes. METHODS: The participants included 7072 residents and 5703 migrants who were registered in the TB Information Management System with smear-positive pulmonary TB from January 2006 to December 2010. The Cochran-Armitage test was employed to test the trends of TSR and logistic regressions to identify the factors associated with treatment outcome. RESULTS: Without subsidies, migrant TB cases had lower odds of successful treatment [OR = 0.20 (95% CI 0.18-0.23)] than resident cases. Subsidisation was associated with a 65% increased odds ratio of success [1.65 (1.40-1.95)] among migrant cases. The TSR has stabilised at 87% for both permanent residents and temporary migrants since 2009. Living in districts with a population density ≥20,000/km(2) was associated with a low odds ratio [0.42 (0.26-0.68)] among resident cases, whereas among migrant cases those living in districts out of central downtown had a higher odds ratio of treatment success [peripheral downtown: 1.73 (1.36-2.20), suburban: 1.69 (1.16-2.46)]. The TB cases in districts with 2.0-2.9 TB specialists/100 cases had a higher odds ratio [2.99 (1.91-4.69)] of successful treatment than cases from districts with fewer specialists. CONCLUSIONS: Besides free medical services, transport and living allowance subsidies to migrant patients with TB improved the treatment outcome significantly.

Do transportation subsidies and living allowances improve tuberculosis control outcomes among internal migrants in urban Shanghai, China?

INTRODUCTION: Tuberculosis (TB) in internal migrants is one of three threats for TB control in China. To address this threat, a project was launched in eight of the 19 districts of Shanghai in 2007 to provide transportation subsidies and living allowances for all migrant TB cases. This study aims to determine if this project contributed to improved TB control outcomes among migrants in urban Shanghai. METHODS: This was a community intervention study. The data were derived from the TB Management Information System in three project districts and three non-project districts in Shanghai between 2006 and 2010. The impact of the project was estimated in a difference-in-difference (DID) analysis framework, and a multivariable binary logistic regression analysis. RESULTS: A total of 1872 pulmonary TB (PTB) cases in internal migrants were included in the study. The treatment success rate (TSR) for migrant smear-positive cases in project districts increased from 59.9% in 2006 to 87.6% in 2010 (P < 0.001). The crude DID improvement of TSR was 18.9%. There was an increased probability of TSR in the project group before and after the project intervention period (coefficient = 1.156, odds ratio = 3.178, 95% confidence interval: 1.305-7.736, P = 0.011). CONCLUSION: The study showed the project could improve treatment success in migrant PTB cases. This was a short-term programme using special financial subsidies for all migrant PTB cases. It is recommended that project funds be continuously invested by governments with particular focus on the more vulnerable PTB cases among migrants.

Factors associated with delayed tuberculosis diagnosis in China.

BACKGROUND: Delays in the diagnosis of tuberculosis reflect a lack of access to care, and contribute to ongoing tuberculosis transmission in the community. The objective of this study was to evaluate the delay in tuberculosis testing and the associated risk factors in Shanghai, Shandong and Sichuan provinces in China. METHODS: A prospective cohort study of 765 culture-positive pulmonary tuberculosis patients registered between December 2006 and December 2008. The delay between the onset of symptoms and tuberculosis diagnosis testing and patient information were recorded in a questionnaire and analysed. RESULTS: The median delay was 36 days and was significantly shorter in patients from Shanghai compared with other places (30 vs. 42 days, P < 0.001). Multivariate analysis revealed that cough in Shanghai patients, lowest income level, being married and presenting expectoration in Shandong and Sichuan patients, were associated with a delay in the diagnosis testing of tuberculosis of >30 days. The only factor associated with a delay of >90 days was, in Shandong and Sichuan provinces only, female gender. The presence of other pulmonary symptoms like haemoptysis and loss of weight, fever and chills could shorten these delays. CONCLUSION: Efforts to shorten delays in the diagnosis of tuberculosis must target vulnerable populations. The non-specific symptom of cough is a risk factor associated with longer delays. Training for healthcare workers in areas with a high incidence of tuberculosis, where a delayed diagnosis in coughers may enhance tuberculosis transmission in the community, is of paramount importance.

The complete mitochondrial genomes of two common shrimps (Litopenaeus vannamei and Fenneropenaeus chinensis) and their phylogenomic considerations.

Complete mitochondrial genomes have proven extremely valuable in helping to understand the evolutionary relationships among metazoans. However, uneven taxon sampling may lead to unclear or even erroneous phylogenetic topologies. The decapod crustaceans are relatively well-sampled, but sampling is still uneven within this group. We have sequenced the mitochondrial genomes of two shrimps Litopenaeus vannamei and Fenneropenaeus chinensis. As seen in other metazoans, the genomes contain a standard set of 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes and an AT-rich non-coding region. The gene arrangements are consistent with the pancrustacean ground pattern. Both the pattern of gene rearrangements and phylogenomic analyses using concatenated nucleic acid and amino acid sequences of the 13 mitochondrial protein-coding genes strengthened the support that Caridea and Palinura are primitive members of Pleocyemata. These sequences, in combination with two previously published penaeid mitochondrial genomes, suggest that genera within the family Penaeidae have the following relationship: (((Penaeus+Fenneropenaeus)+Litopenaeus)+Marsupenaeus). The analyses of nucleic acid and amino acid sequences of the mitochondrial genomes also strongly support the monophyly of Penaeidae, Brachyura and Pleocyemata. In addition, the analyses of the average Ka/Ks in the 13 mitochondrial protein-coding genes of penaeid shrimps indicated a strong purifying selection within this group.